Some printing apparatuses have various paper supplying ports (paper supplying methods) depending on the types of paths along which print paper sheets are fed, and the stock forms of paper sheets. For example, as paper supplying paths, a paper supplying port that uses a J path or straight path as a relatively flat paper feeding path for paper supply and after paper supply, and a complicated paper feeding path after paper supply such as a U-turn path or the like are known. Also, an “automatic paper supplying port” for automatically supplying paper sheets set on a tray one by one, a “manual paper supplying port” for manually supplying a paper sheet to a position near a print head unit by the user, a “cassette paper supplying port” for stocking paper sheets in large quantities in a cassette-like case or the like in advance, and automatically supplying paper sheets from that case, and the like are available.
A paper supplying port which uses a flat path free from any warp of paper sheets is often used when high-resolution photos are printed on high-grade paper sheets or the like. On the other hand, a straight path manual paper supplying port is often used in a thick paper printing apparatus which forms book jackets or the like.
When a printing apparatus having a plurality of paper supplying ports suffers a paper-out state during printing, it is desired to notify the user of not only such paper-out state but also a paper supplying port for which paper sheets are to be set. In order to realize such notification, a technique for prompting the user to set paper sheets at a paper feeding port used until just before when a paper-out state has occurred is known (e.g., Japanese Patent Laid-Open No. 8-118753).
Depending on the print purpose, when a paper-out state has occurred at a given paper supplying port, the user may want to restart printing by switching that paper supplying port to another paper supplying port. On the other hand, when a paper-out state has occurred at a given paper supplying port, the user may also want to restart printing by loading paper sheets at that paper supplying port.